i would think that a stage 3 chip would be pre-programed for stage 3 aftermarket bits like intercooler, pumps, injectors, turbo and the like. so if youve got one it might be usless without the other bits maybe??
im worried as to you not asking this question from the seller in the first place. sounds iffy, did you by off ebay or somthing?? normally aftermarket chips go into and replaces the stock ecu chip.